Road tractors are generally used to pull trailers on roads to transport cargo. Aerodynamic apparatuses can be installed on the road tractor and/or on the trailer in order to reduce the aerodynamic air drag and improve fuel efficiency.
Rear drag-reducing apparatuses are generally installed and secured to a rear portion of a trailer to help aerodynamically manage the flow of air behind the trailer. It is known that a significant amount of air drag is resulting when a vehicle travels on a road; this is due to an area of low pressure created at the rear end of the vehicle. For example, with a tractor-trailer type vehicle, the air makes a sharp bend around the squared-off back of the trailer, thus causing turbulence and drag on the vehicle. To overcome this problem, increased engine power is required and therefore undesired increased fuel consumption. Furthermore, the turbulence also causes poor visibility in rainy conditions around the vehicle and an accumulation of dirt on the back of trailers.
In the trucking industry, the aerodynamics of vehicles to reduce fuel consumption is a growing concern. Tests indicate that fuel savings from aerodynamic improvements are equivalent to fuel savings attained by a chassis weight reduction and require fewer services to maintain. The air resistance or aerodynamic drag of the vehicle increases the power needed by the engine as the speed increases. It is generally known that, for example, a tractor-trailer needs about 100 horsepower (HP) to overtake the air drag at a speed of 55 MPH. Approximately half the energy reaching the drive wheels is required to overcome air resistance at cruising speed. Recent tests reveal that the square back end contributes approximately to 30% of the air drag. Therefore, the addition of aerodynamic devices, such as a rear deflector, diminishes the air drag and results in lower fuel consumption.
Rear-deflectors are preferably expandable automatically when the vehicle cruising conditions are met to maximize fuel economy. However, the automatic system is detrimental to manual actuation of the rear-deflectors. Manual actuation of the rear-deflector can be desirable to bypass the automatic system in case of need.
Therefore, it exists a need in the art for an improved air drag reducing apparatus over the existing art. There is a need in the art for such an air drag reducing apparatus that can be easily expanded and retracted. There is also a need for an air drag reducing apparatus that can be automatically expanded and retracted depending of the vehicle's behaviors. There is also a need in the art for an improved air drag reducing apparatus of which automatic behaviors can be bypassed to manually expand and retract the air drag reducing apparatus. Moreover, there is also a need for an air drag reducing apparatus assembly that is using GPS data to automatically expand and retract the air drag reducing apparatus depending of the vehicle's behaviors.